Objectionable bathroom odor is of particular concern to many people. A great deal of inventive energy has been expended in the pursuit of eliminating bathroom odors. Despite the efforts spent on solving this problem which is as old as the advent of indoor plumbing, the present inventor finds the prior art solutions to be lacking in several important aspects.
The preponderance of the prior art toilet ventilators use the approach of gathering the odoriferous gasses from the space within the toilet bowl and exhausting these gases to the exterior of the building. Such systems are described in U.S. Pat. Nos. 2,847,682; 3,069,696; 3,938,201; 4,007,498; 4,017,916; 4,103,370; 4,620,329; and 4,701,966. While this exterior ventilation approach may be effective at eliminating odors in a brute-force manner, it is highly inefficient from the viewpoint of energy conservation. If such a system is used in a heated or air conditioned bathroom, the air which comes in to make up for the exhausted air must be heated or cooled at the expense of considerable energy.
Another common prior art approach attempts to overcome the energy inefficiency of exterior exhaust systems by removing the odor containing air from within the toilet bowl, filtering it or adding fragrance and exhausting the air within the interior of the bathroom. Systems using this approach are described in U.S. Pat. Nos. 3,230,551; 3,491,382; 3,571,824; 3,857,119; and 5,161,262. This approach may eliminate the wasted energy of exterior exhaust systems by returning the air to the room, but the approach is ultimately self defeating. No matter how effective the filtering or fragrance system is, it cannot remove all of the odor causing agents from the air and the fact remains that the system is taking odor ridden air from within the toilet bowl, partially removing the effluents, and exhausting it to the bathroom atmosphere where it is far more likely to be breathed in by the occupants of the bathroom. This disadvantage may become even more noticeable as the filter element nears the end of its useful life. A saturated filter may actually begin to return absorbed odors to the room air, exacerbating the odor problem rather than curing it.
In order to eliminate the energy inefficiency of exterior exhaust systems and the self-defeating nature of interior exhaust systems, the present invention uses a recirculation approach which draws air from within the toilet bowl, filters out odors, adds a fragrance, then returns the air to the toilet bowl, not to the room. This closed-system recirculating approach is highly effective and highly energy efficient. Only one prior art patent has been found that attempts to use a recirculation approach. This patent, U.S. Pat. No. 4,433,441, however, has only one mode of operation and lacks many of the other features important to the present invention, such as a room air freshening function and a comfort heater.
Another related area of technology includes toilets or toilet attachments for washing and drying the occupant after use of the toilet. This technology is exemplified in U.S. Pat. Nos. 4,087,871 and 4,653,126. These patents are mentioned because they both include a heated air source which blows hot air into the toilet bowl interior to dry the user. This approach should not be confused with the comfort heater function of the present invention. The hot air blowers in these prior art patents create a positive pressure inside the toilet bowl which would disperse the odor filled air from within the toilet bowl, exacerbating any odor problem rather than solving it.